A gear motor assembly, such as a window lift drive used in a vehicle to raise or lower a window, typically includes a bidirectional motor and a gearbox. The gearbox includes a casing and a gear train in the form of a worm and worm gear disposed in the casing. The motor includes a stator and rotor rotatable relative to the stator. The rotor includes a motor shaft, a core and a commutator fixed to the motor shaft. The motor shaft extends into the gearbox casing and has a worm which is meshed with the worm gear to rotate the worm gear.
The stator includes a motor housing, multiple magnets installed in an inner surface of the motor housing, and a brush assembly fixedly mounted to one end of the motor housing. The brush assembly includes a brush holder and multiple brushes each slidably received in a respective chamber of the brush holder. Gaps are formed between the brush and the inner surfaces of the chamber to allow the brush to slide through the chamber. Each brush is substantially perpendicular to a rotational axis of the commutator, and is urged towards the commutator by a spring which provides a force along the length of the brush. However, this type of motor will cause undesired vibration due to the gaps between the brushes and the respective chambers.
Therefore, there is a desire for a gear motor assembly with an improved brush assembly.